Total depth after etching is 18.254 um
Calculated remaining resist as 8.45um, indicating an erosion of 0.29um in 10 minutes of etching
This equates to an erosion rate of 29 nm/min
The etch depth of 9.80um in 10 mins indicates an etch rate of 980.0nm/min
The selectivity is therefore 34.12:1